1. Technical Field
This disclosure relates to trimming voltage-mode band-gap reference circuits to a desired output voltage which meets a temperature drift specification.
2. Description of Related Art
Various applications may require a reference voltage that meets a temperature drift specification, such as digital-to-analog converters. A voltage reference circuit, such as a voltage-mode band-gap reference circuit, may be used to provide this reference voltage. Examples of such circuits are set forth in U.S. Pat. Nos. 7,420,359 and 6,329,804.
A voltage-mode band-gap reference circuit may exhibit its greatest temperature stability at a particular voltage, commonly known as the “magic” voltage of the circuit. However, it may be difficult to generate an output voltage which is near or below this magic voltage.
A voltage-mode band-gap reference circuit may use a second stage to generate the output voltage. However, the second stage may introduce noise which may be difficult to filter.
A voltage-mode band-gap reference circuit may require a supply voltage which is much higher than the magic voltage. Such a high supply voltage, however, may be unavailable in certain applications.
A voltage-mode band-gap reference circuit may be difficult and time consuming to trim.